From the front it would look fine and dandy. From the back it would look slightly odd due to an overhang on the lower horn side of the neck pocket, but I do not look at the back of a neck so I would not be bothered. From above it would look fine because it would sit on top of the bass and not really be obvious that there was a lip protruding further than the heel. It would make more sense just to rout the body which is probs what I will do, I was just musing really. Not really thinking about resale, but if a 5 string neck which would fit into a 4 string P pocket and turns it into a 35" 19mm P (with new bridge and pick up) then I would bet that there would be a fair few on here who would be interested.